Venus flytrap

The Venus flytrap is a carnivorous plant that catches insects in hinged traps. It counts. Each trap has a few tiny trigger hairs, and a single touch does nothing. Only if a hair is touched twice within about twenty seconds does the trap snap shut, in about a tenth of a second.^[1] Botanists believe this stops the plant wasting its energy on raindrops and falling leaves, and makes it the only plant that asks for a second opinion.

Counting to five

Once the trap has shut, the struggling insect keeps touching the trigger hairs. A 2016 study found that after about five touches the plant starts producing digestive juices.^[2] The more the insect struggles, the more the plant digests. It is the only meal in nature that is arranged entirely by the guest.

• One touch: ignore.
• Two touches: shut.
• Five touches: dinner.

Home

Despite being sold all over the world, the Venus flytrap grows wild in only one small area: boggy ground within roughly a hundred miles of Wilmington, in North and South Carolina in the United States. It does not catch many flies, in fact; most of its meals are ants, beetles and spiders that walk in. It is a flytrap mainly in the sense that a doormat is a welcome.

See also

• Door – another hinged thing that shuts
• Number 7 – two more than it needs
• Doormat – the other welcome

References

1. Snap, S. (2016). “It Counts”. Current Plant Biology 5: 2.
2. Hinge, H. (1999). A Second Opinion. Bog Press.
3. Trigger, T. (2008). “Twenty Seconds”. Botanical Timing 1: 1.